/* * Neighbor Discovery snooping for Proxy ARP * Copyright (c) 2014, Qualcomm Atheros, Inc. * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include <netinet/ip6.h> #include <netinet/icmp6.h> #include "utils/common.h" #include "l2_packet/l2_packet.h" #include "hostapd.h" #include "sta_info.h" #include "ap_drv_ops.h" #include "list.h" #include "x_snoop.h" #include "ndisc_snoop.h" struct ip6addr { struct in6_addr addr; struct dl_list list; }; struct icmpv6_ndmsg { struct ip6_hdr ipv6h; struct icmp6_hdr icmp6h; struct in6_addr target_addr; u8 opt_type; u8 len; u8 opt_lladdr[0]; } STRUCT_PACKED; #define ROUTER_ADVERTISEMENT 134 #define NEIGHBOR_SOLICITATION 135 #define NEIGHBOR_ADVERTISEMENT 136 #define SOURCE_LL_ADDR 1 static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr) { struct ip6addr *ip6addr; ip6addr = os_zalloc(sizeof(*ip6addr)); if (!ip6addr) return -1; os_memcpy(&ip6addr->addr, addr, sizeof(*addr)); dl_list_add_tail(&sta->ip6addr, &ip6addr->list); return 0; } void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta) { struct ip6addr *ip6addr, *prev; dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr, list) { hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr); os_free(ip6addr); } } static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr) { struct ip6addr *ip6addr; dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) { if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] && ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] && ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] && ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3]) return 1; } return 0; } static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len) { struct sta_info *sta; for (sta = hapd->sta_list; sta; sta = sta->next) { if (!(sta->flags & WLAN_STA_AUTHORIZED)) continue; x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len); } } static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf, size_t len) { struct hostapd_data *hapd = ctx; struct icmpv6_ndmsg *msg; struct in6_addr saddr; struct sta_info *sta; int res; char addrtxt[INET6_ADDRSTRLEN + 1]; if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) return; msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN]; switch (msg->icmp6h.icmp6_type) { case NEIGHBOR_SOLICITATION: if (len < ETH_HLEN + sizeof(*msg)) return; if (msg->opt_type != SOURCE_LL_ADDR) return; /* * IPv6 header may not be 32-bit aligned in the buffer, so use * a local copy to avoid unaligned reads. */ os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr)); if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 && saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) { if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN) return; sta = ap_get_sta(hapd, msg->opt_lladdr); if (!sta) return; if (sta_has_ip6addr(sta, &saddr)) return; if (inet_ntop(AF_INET6, &saddr, addrtxt, sizeof(addrtxt)) == NULL) addrtxt[0] = '\0'; wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for " MACSTR, addrtxt, MAC2STR(sta->addr)); hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr); res = hostapd_drv_br_add_ip_neigh(hapd, 6, (u8 *) &saddr, 128, sta->addr); if (res) { wpa_printf(MSG_ERROR, "ndisc_snoop: Adding ip neigh failed: %d", res); return; } if (sta_ip6addr_add(sta, &saddr)) return; } break; case ROUTER_ADVERTISEMENT: if (hapd->conf->disable_dgaf) ucast_to_stas(hapd, buf, len); break; case NEIGHBOR_ADVERTISEMENT: if (hapd->conf->na_mcast_to_ucast) ucast_to_stas(hapd, buf, len); break; default: break; } } int ndisc_snoop_init(struct hostapd_data *hapd) { hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc, L2_PACKET_FILTER_NDISC); if (hapd->sock_ndisc == NULL) { wpa_printf(MSG_DEBUG, "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s", strerror(errno)); return -1; } return 0; } void ndisc_snoop_deinit(struct hostapd_data *hapd) { l2_packet_deinit(hapd->sock_ndisc); }